Painful, swollen or bleeding gums are a sign of gum disease (periodontal disease). Gum disease can vary from the mild swelling of gums (and bleeding) through to more serious gum disease that may result in damage to tissue and bone which support teeth.
Poor oral hygiene resulting in a buildup of plaque and tartar (calculus) which left untreated can lead to mild gum disease or Gingivitis. If Gingivitis is also left untreated it can lead to Periodontitis a more serious form of gum disease.
Mild gum disease or gingivitis can be treated by improved oral hygiene as well as regular dental cleanups. Ensuring that you visit the dentist regularly as well as brush and floss regularly to maintain good oral hygiene is the best way to treat and prevent any gum disease.
If Gingivitis is left untreated it can result in more serious periodontitis which can ultimately lead to a loss of teeth.